Flutter Get firebase collection data to list of object - list

Question

I have a class name Todo
class TodoField {
static const createdTime = 'createdTime';
}
class Todo {
DateTime createdTime;
String title;
String id;
String description;
bool isDone;
Todo({
#required this.createdTime,
#required this.title,
this.description = '',
this.id,
this.isDone = false,
});
}
My data is saved in collection name: MyTodos. I want to add a collection in a list like List<Todo> _todo=[Todo...]

Answer 1

I'd advise creating a fromJson factory method to this Todo class, that way mapping the Firebase documents' data to a strongly-typed PODO (Plain Ol' Dart Object) is easier to manipulate in Flutter.
Your updated Todo class would look like:
class Todo {
DateTime createdTime;
String title;
String id;
String description;
bool isDone;
Todo({
#required this.createdTime,
#required this.title,
this.description = '',
this.id,
this.isDone = false,
});
factory Todo.fromJson(Map<String, dynamic> json) {
return Todo(
createdTime: json['createdTime'],
title: json['title'],
id: json['id'],
description: json['description'],
isDone: json['isDone']
);
}
}
Then, wherever you're pulling the Firebase data from your collection ** MyTodos**, you should do the mapping, as such:
QuerySnapshot snapshot = await FirebaseFirestore.instance.collection('MyTodos').get();
List<Todo> _todos = snapshot.docs.map((d) => Todo.fromJson(d.data())).toList();
Then you can do anything you want with your _todos collection. For example, inside a provided service, you can grab the data as follows:
class TodosProvider extends ChangeNotifier {
Future<List<Todo>> GetData() async {
QuerySnapshot snapshot = await FirebaseFirestore.instance.collection('MyTodos').get();
List<Todo> _todos = snapshot.docs.map((d) => Todo.fromJson(d.data())).toList();
return _todos;
}
}
Then in your widget's build method you can consume this provider as such:
#override
Widget build(BuildContext context) {
// obtain the provided service
// make sure this service is injected at the root via
// either a ChangeNotifierProvider or MultiProvider
var todos = Provider.of<TodosProvider>(context, listen: false);
return Scaffold(
body: FutureBuilder(
future: todos.GetData(),
builder: (context, snapshot) {
if (snapshot.hasData) {
// here consume your Todos
List<Todo> todos = snapshot.data as List<Todo>;
// put them in a list or whatever you want
}
return CircularProgressIndicator();
}
)
);
}